Former champion Jelena Ostapenko reached the third round by beating second-seeded Karolina Pliskova 6-4, 6-2.
Ostapenko won her only major title here in 2017.
Pliskova reached the semifinals that year and lost to Simona Halep.
There were blue skies over Roland Garros after days of rain but the roof stayed over Court Philippe Chatrier for their match.
The unseeded Latvian player next faces 29th-seeded Sloane Stephens or Paula Badosa.
Pliskova’s twin sister, Kristyna, was also playing a former French Open champion when she faced 2016 winner Garbine Muguruza.